
void main () {
  // var 变量名 = 表达式;
 // var username = '老高';  // String username = "老高";
  var age;
  age = 10;
  age = "老高";
  age = false;

  print(age);
  String username = "老高";
  print(username);
  username = "老高你混蛋";
  print(username);

 // username = 20;

 // const 是编译期常量，值在编译期的时候赋值的
 // final 是运行时常量, 值在运行时赋值
 const baseURL = "https://toutiao.itheima.net/";
 print(baseURL);

 final baseURL2 = "https://toutiao.itheima.net/";
 print(baseURL2);

 int x = 1;
 int y = 2;
 final count = x + y ;
 print(count);

 const count1 = 1 + 2;
}